Model 659 parts question

[Zebra3]

They're all three decades old now, parts are scarce and getting scarcer. I've bought a Wolff spring kit for mine, as well as a spare barrel bushing, and getting a firing pin. What other spare parts would you suggest squirreling away in the interest of keeping her running for the foreseeable future?

[W.E.G.]

You can never have too many firing pins, extractors, and extractor springs.

You are always just one failed cartridge case away from needing replacements.